Just a suggestion about removing the center cluster of the instrument panel --- pull battery terminals off BEFORE you unscrew the oil pressure line. This will insure you don't absent mindedly start turning over the engine before you 'remember' you forgot to screw it back on... or create a mess.
To test the lights before everything's buttoned back up, partly install the instruments in the panel holes, hooked up and grounded though (or the instrument lights won't work), put the battery terminals back on and turn on the lights....don't start the engine! If the lights work, then pull them back out install the tack, then the center cluster WITH the oil pressure line this time, finally the Speedo. I always start the engine AFTER I attach the oil pressure line, but before pushing the center cluster all the way back into it's hole to make sure there's no oil leakage! My biggest fear is that I'll cross thread the oil line attachment and find out a few days later with oil dripping on my pants driving down the road.
BTW, I have BIG hands AND an A/C.... soooooo... not only do I skin up my hands installing the tach I have to pull the AC unit down to pull the radio panel out (and radio of course) to get access to the Speedo and Center Cluster to unhook them... I can almost do this in my sleep now I've done it so many times, but it's a real chore with having to drop the AC unit.... no fun at all. The instruments are a breeze (except for my skinned knuckles with my big hands), compared to dropping the AC unit down (actually, it's getting the AC unit back up and attached again that's the time & effort consumer).
Next time I do it (winter) I'm doing the bezel cleaning thing, AND removing & rechrome or replace windshield chrome (access to the 4 nuts holding it down (2 for the left side, 2 for the right) are from under the dash .... so instruments and glovebox out.... and while they're out I'll pull the heating/ventilator disks asm to buff / polish (the tops / bottoms of the plastic levers... especially my 'clear' one), and replace the illumination bulbs in that asm (nothing wrong with the current ones, but they're the originals still and I'm sure one or more will go out right after I have everything.
Of course the real reason for all the above is I need to replace my windshield glass & rubber molding --- orig. glass is visibly fine pitted and difficult see thru when sun's low in the sky ---- and either replace or rechrome the garnish molding... and have the upper body panel (at the bottom of the windshield exterior) properly painted... the masking job on the paint job was nearly perfect, but when I replace the rubber there'll be a tiny paint uplifted (rough) edge at the new rubber edge... and while the window's out I might as well take care of that before I start kicking myself for not doing it when it was easy to have done.
BTW, the guy I use for paint now is a blending pro... unbelievable! He was recommended to me by a frame-up MB restorer in the area.
Longtooth
67 250SL US #113-043-10-002163
95 SL500
